Productivity Power Tools - Extension for Visual Studio - A set of extensions to Visual Studio 2012 Professional (and above) which improves developer productivity.
Monkey Test It - Primate powered algorithms that scan your site for common bugs and SEO mistakes.
CodeRush - DevExpress CodeRush for Roslyn uses significantly less memory, works faster, and lets you start Visual Studio faster.
Reflect.run - Reflect is automated web testing that anyone can use. It requires no code, and no installation. Record once, run anytime.
ReSharper - ReSharper is a productivity tool for visual studio that provides tools and features to help you manage your code.
BugBug.io - BugBug makes test automation ultra-simple. It allows you to automate testing without coding, ensuring the quality of your web app or website without repetitive manual testing or writing a line of code.